Baihetan Hydropower Station | A Hundred Year Dream of One Million Units
North Star Hydroelectric Network News: The joyful song of water flow is singing on the Jinsha River.
On June 28th, the world's first batch of million kilowatt hydropower units were successfully put into operation at the world's second largest hydropower station, the Baihetan Hydropower Station, built by the Three Gorges Group. In the blink of an eye, they transformed the surging river into "China Energy" under the name of electricity.
Million kilowatt units, 100% made by China's "intelligence".
This turn has erected a historic monument to the century long struggle of China's hydropower industry, and opened the door to the world's "unmanned zone" of China's hydropower industry.
This turn indicates that the Chinese people have the ambition, confidence, and ability to continuously reach new heights in hydropower technology one after another.
Where did the million kilowatt unit come from and where will it go? Let's search for answers in the context of history and reality.
Coming from history
The Jinsha River, with its countless twists and turns, gathers majestic power in the canyon. Inside the secluded mountain, the builders are painting a long scroll with splashing ink, depicting the middle current hitting the water.
On June 21, 2020, a precision "Chinese core" with a diameter of over 8 meters and a weight of about 350 tons was accurately embedded in the "heart" of the Baihetan Hydropower Station, and the runner of the world's first 1 million kilowatt hydroelectric generator unit was successfully lifted.
Looking back a hundred years ago, the impoverished and weak old China did not have this "confidence".
In 1912, two 240 kW units developed abroad were put into operation in Shilongba Hydropower Station, the first hydropower station in Chinese Mainland. When they brought the first light to illuminate the path of industrialization dream to Kunming, they also deeply awakened China's expectation: when will China have its own developed hydroelectric units?
Until the end of 1949, when the People's Republic of China was established, the installed capacity of hydropower in China was only 360000 kilowatts, and all units were developed by foreign countries.
From only 360000 kilowatts nationwide to one million kilowatts, the founding of the People's Republic of China, the leadership of the CPC, and the continuous efforts of the national electromechanical workers have started the great journey of "changing fate against the weather" of China's hydropower units:
——In 1952, an 800 kilowatt unit was successfully installed at the Xiadong Hydropower Station in Sichuan, ending China's history of not being able to independently design and manufacture hydroelectric units.
——In 1958, the construction of China's first million kilowatt level hydropower station, Liujiaxia Hydropower Station, began with a single unit capacity of 300000 kilowatts, and the core components were manually polished by craftsmen. In the same year, the concept of developing 600000, 800000, or even 1 million kilowatt hydroelectric units was proposed at the National Science Planning Conference.
——In 1987, the 320000 kilowatt unit of Longyangxia Hydropower Station was put into operation.
In the late 1980s, the spark of domestically produced hydroelectric units gradually showed a trend of starting a prairie fire. However, compared to the nearly 700000 kilowatt hydroelectric units developed by developed countries, China still lags behind by about 30 years. It wasn't until the 1990s that there was an opportunity to change from following to running in parallel, and even to start leading.
During the development process of the 700000 kilowatt unit on the left bank of the Three Gorges Project, the Three Gorges Group, which was also known as the "China Three Gorges Project Development Corporation" at that time, took the lead in conducting scientific and technological research, collaborating with domestic enterprises such as Harbin Electric and Dongfang Electric to learn international advanced experience, gradually transitioning to independent innovation, and ultimately mastering the core technology of the overall design and manufacturing of the 700000 kilowatt unit.
As for the development of the right bank unit of the Three Gorges Project, China's hydropower unit research and development team has the ability to compete with international hydropower giants and successfully develop and put into use 700000 kilowatt units.
In 2008, more than 40 experts evaluated the performance of the Three Gorges units and concluded that the overall performance of the domestically produced units on the right bank was better than that on the left bank, with key performance reaching the same international level.
Taking this as a new starting point, in 2013, Xiluodu Hydropower Station had 770000 kilowatts, Xiangjiaba Hydropower Station had 800000 kilowatts... In 2021, the 1 million kilowatt unit of Baihetan Hydropower Station was successfully put into operation, which amazed the world.
From scratch, from small to large, from weak to strong.
This arduous history of domestic development of hydropower units embodies the lofty pursuit of Chinese hydropower personnel to "serve the country through industry". Its every progress is inseparable from the strong leadership of the CPC; Every development of it is closely linked to the fate of the country and nation.
Shake hands with the New Era
The idea of building the Baihetan Hydropower Station can be traced back to the 1950s. The Yangtze River Water Resources Commission of the Ministry of Water Resources has organized multiple survey and design units to conduct a survey on the development of water resources in the Jinsha River Basin.
In 1990, the "Brief Report on the Comprehensive Utilization Plan of the Yangtze River Basin (Revised in 1990)" was approved by the State Council, specifying the need to carry out preliminary work for Wudongde, Baihetan, Xiluodu, and Xiangjiaba hydropower stations in the lower reaches of the Jinsha River.
In 1950, the per capita electricity generation in China was less than 3 kilowatt hours, but the per capita electricity generation in the United States exceeded 2900 kilowatt hours. To achieve industrialization, China's electricity demand will inevitably undergo a significant growth process, "said Wang Yinan, a researcher at the Development Research Center of the State Council.
But the length of the river is limited, and relying solely on the increase in the number of power stations is not a long-term solution. We must solve the research and development difficulties of large capacity units and improve power generation efficiency.
The Baihetan million kilowatt unit, which undertakes the mission of "West East Power Transmission", was born in the logic of historical progress and "fulfilled its duties" in the trend of the times——
Externally, it showcases its technological content, showcasing the strength of the country and the confidence of the nation; Internally, it unleashes the potential of "one million kilowatts" to better serve social production and benefit people's lives.
After the Baihetan Hydropower Station is put into operation and generates electricity, it will transmit electricity to Jiangsu and Zhejiang. One unit can rotate for one hour and supply 500000 household induction cookers; By rotating 16 units for 1 hour, 8 million household induction cookers can be supplied.
"It can not only provide clean, economical and safe electricity, strongly support the development of the Yangtze River Economic Belt, but also optimize and adjust the energy structure of the Yangtze River Economic Belt," said Niu Xinqiang, an academician of the CAE Member.
The high-quality development of the economy and society calls for the birth of large-scale clean electricity; Expanding the single unit capacity can reduce the number of units, which is beneficial for the layout of hub projects and saves investment; As far as large capacity units can meet the long-term development of power grid... It is extremely necessary to develop million kilowatt units.
But to turn this giant unit from a vision into a reality, it is necessary to evaluate the maturity of various aspects such as natural and technological conditions.
The installation scale of Baihetan Hydropower Station is large, with a water head of over 200 meters, a large drop, and a large flow rate, which makes the million kilowatt units useful. "Zhang Chengping, Chief Engineer of Mechanical and Electrical Engineering at Three Gorges Group, said," Only with large capacity units can we better adapt to engineering conditions, fully utilize engineering benefits, and utilize water resources more reasonably and efficiently
If technology is considered, the development of a million kilowatt unit can be approached through the localization of units in hydropower stations such as the Three Gorges Project, Xiluodu, and Xiangjiaba.
At the right bank power station of the Three Gorges Project, we boldly adopt the stator and rotor full air ventilation cooling technology. Compared to the water internal cooling technology, the process is simple, the failure rate is low, and it is easy to maintain
At Xiluodu Hydropower Station, we have successfully developed a 200 meter head section turbine with excellent comprehensive performance in terms of efficiency, cavitation, stability, and other aspects
Hu Weiming, General Manager of the Three Gorges Construction Group under the Three Gorges Group, said that these key technologies have laid a solid foundation, added experience and confidence for the development of the Baihetan million kilowatt unit.
Bu Liangfeng, the deputy chief engineer of Harbin Electric Power, who has participated in the subcontracting manufacturing of embedded parts for the Three Gorges left bank unit, said that in the development process of the Three Gorges Project left bank unit, the high-strength steel plate of the 60 kilogram spiral case must be imported from abroad at a high price.
In order to overcome the bottleneck of imported materials, Three Gorges Group led the scientific research and organized sister units such as Ansteel and Baowu Steel to independently innovate, ultimately allowing the right bank unit to use domestically produced steel.
Nowadays, the domestically produced high-strength steel used in the manufacturing of the spiral case of the Baihetan Hydropower Station has reached the level of 80 kilograms. The key materials required for the million kilowatt unit, such as high-strength magnetic yoke steel plates, tear resistant thick steel plates, and high-grade silicon steel sheets, have all been domestically produced.
In addition, in terms of supporting equipment, from bridge cranes, busbars, large transformers, to speed control systems, excitation systems, monitoring systems... China's hydropower equipment industry chain is constantly upgrading, and has also become one of the assistance for China's million kilowatt units to reach the world's "hydroelectric peak".
With confidence, one has courage.
Since 2006, relying on key projects, Three Gorges Group has once again joined forces with East China Survey and Design Institute, Yangtze River Survey and Design Institute, Harbin Electric Power, Dongdian, and others to organize and lead scientific research and research on million kilowatt hydropower units with a scientific and prudent attitude.
This research project has gone through three stages and more than ten years. Multiple studies and experiments have been conducted on key technologies such as overall technology, hydraulic design, electromagnetic design, 24/26 kV line rods, ventilation and cooling, thrust bearings, structural stiffness and strength, manufacturing and processing, and raw materials, achieving rich research results and laying a solid foundation for the successful development of Baihetan million kilowatt units.
This scientific research breakthrough is officially advancing towards the "unmanned zone" of the world's hydropower core equipment with firm and powerful steps.
Walking alone in the world "unmanned zone"
Behind the long journey of a million kilowatt unit from 0 to 1, there is a gradual accumulation of 0.1 or even 0.01 steps.
At present, among the 127 hydropower units with a capacity of over 700000 kilowatts under construction worldwide, there are only a few units with a capacity of over 800000 kilowatts, and the "million kilowatt unit" is a tangible "unmanned zone".
Some people wonder why it's so difficult?
A million kilowatt unit needs to have excellent energy conversion efficiency and good hydraulic stability performance in order to operate smoothly for a long time under various operating conditions.
The million kilowatt unit has a higher applied water head and speed, and its size is similar to that of the Three Gorges unit. Therefore, its external load is greater and requires higher structural materials, such as the strength of the magnetic yoke steel plate to reach 750 MPa or above, and the high-strength steel plate for the spiral case to reach 800 MPa.
For a million kilowatt unit, the thrust load of the thrust bearing is slightly greater than that of the Three Gorges unit, but the unit speed is higher, the PV value of the thrust bearing is greater, and the manufacturing difficulty is greater.
A million kilowatt unit with a generator rated current that exceeds the rated current range of existing generator voltage equipment applications requires increasing the generator rated voltage to over 24 kV in order to meet the requirements.
Is it difficult? Of course it's difficult!
Taking the runner, the core component of a million kilowatt water turbine, as an example, it bears a huge hydraulic energy with a maximum head of over 240 meters and a diameter of over 8.5 meters, embodying the most exquisite design of a water turbine generator set.
Without standards, experience, and reference, Wei Xian, the leader of hydraulic design and research at Harbin Electric Power, led a team to "ignore" almost all holidays in the past 8 years, typing hundreds of thousands of lines of code, building a simulation experimental platform, and after hundreds of optimization calculations and experiments, repeated comparison and demonstration, the development of a runner model emerged.
Despite the large size of the runner, the details are extremely demanding: blades weighing over 8 tons must be poured into shape at once, and the composition and temperature of the molten steel in different furnaces must be consistent at all times; After the shovel grinding process, the iron filings cut can reach several tons; It is also necessary to choose several options for welding and turning over only once
Facing a giant hydroelectric generator set assembled with approximately 60000 parts, it is necessary to conduct research and optimization on hundreds or thousands of design, manufacturing, installation and other topics in order to achieve the optimal overall performance. There is only one path - technology first, there is a possibility of optimization.
The electromechanical technology center team responsible for the design and manufacturing management of the Baihetan unit, in the unit design management, is meticulous in every design detail and every parameter indicator, ensuring that the design has "zero doubts"; In the management of unit manufacturing, the team ensures "zero defects" in manufacturing with the highest standards, optimal processes, and strictest control.
They carry out rounds of design and manufacturing reviews, striving to identify potential defects and risks, drawing on past power plant experiences and lessons, learning from each other's strengths and weaknesses, and continuously optimizing and improving unit performance.
They vigorously promote "three-dimensional design" and "beautiful electromechanical", optimize the layout of pipelines, cables, etc., while ensuring the internal quality of the unit, improve the appearance quality of the equipment, and achieve "both internal and external excellence".
First-class design and manufacturing require first-class installation and debugging.
At the installation and commissioning site of the unit, Kang Yonglin, Director of the Mechanical and Electrical Installation Project Department of the Baihetan Engineering Construction Department of the Three Gorges Group, led his disciples Jin Kun, Chen Hao, Chen Xupeng, and others to build two "classrooms"——
One hall is located in a giant unit. The installation and debugging process of every equipment, including wheel welding, rotor yoke installation, ventilation and cooling system debugging, is the best teacher.
The first hall is located in the electromechanical innovation studio. Sharing practical experience, identifying knowledge loopholes, and exploring research directions... Every employee should boldly speak up on stage.
During the installation of the rotor yoke, the Dongdian service team ensured the "result quality" with "process quality", and the average daily time spent on site exceeded 16 hours. The measurement data shows that compared to the theoretical center, the deviation of the stacked magnetic yoke center does not exceed 0.02 millimeters, which is much higher than the industry standard for high-quality units.
On the way to attack the fortress, we are not advancing alone. People along the way are working together to explore——
Engineers from design units such as the East China Academy are burning midnight oil in front of computer screens, drawing "blueprints" one after another; The technical personnel of installation units such as Gezhouba and the Fourth Bureau of Water and Electricity, tirelessly checked the installation measurement data on site over and over again; More than a hundred power plant experts and operation and maintenance backbone from Three Gorges Group Changjiang Power Plant have taken up their positions in advance and are ready to depart, ready to pick up at any time
Relying on the research and development of a million kilowatt unit, the progress of Chinese electromechanical personnel is comprehensive. This process not only trains the team, but also condenses the spirit of daring to be the first in the world, "said Fan Xiaxia, a member of the Three Gorges Group's party group and deputy general manager.
Looking back at the century long journey and looking forward to the million kilowatt unit, the thorny belts that pricked hands during climbing and the rugged roads that were worn and bleeding are clearly visible.
But it is precisely because of the difficulty that walking is great.
Those perilous peaks that have been traversed are able to cross time and space, making a note for a journey; The magnificent peak scenery allows for the removal of clouds and calls for the next climb.
